Amphiphilic macromolecule and the purpose of this amphiphilic macromolecule

ABSTRACT

Amphiphilic macromolecules having structural units to adjust molecular weight and molecular weight distribution and charging property effects, high stereo-hindrance structural units, and having amphiphilic structural units. The Amphiphilic macromolecules are suitable for fields such as oil field well drilling, well cementation fracturing, oil gathering and transfer, sewage treatment, sludge treatment and papermaking, etc., and can be used as an oil-displacing agent for enhanced oil production, a heavy oil viscosity reducer, a fracturing fluid, a clay stabilizing agent, a sewage treatment agent, a papermaking retention and drainage aid or a reinforcing agent, etc.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a national stage entry of PCT/CN2011/001578 filedSep. 16, 2011, which claims priority to Chinese Patent Application No.201110210344.1, filed on Jul. 26, 2011, said applications are expresslyincorporated herein in their entirety.

TECHNICAL FIELD

This invention relates to an amphiphilic macromolecule and uses thereof,and this amphiphilic macromolecule is applicable to oilfield drilling,well cementing, fracturing, crude oil gathering and transporting, sewagetreating, sludge treating and papermaking, and it can be used asintensified oil producing agent and oil displacing agent, heavy oilviscosity reducer, fracturing fluid, clay stabilizer, sewage treatingagent, retention aid and drainage aid and strengthening agent forpapermaking.

BACKGROUND OF THE INVENTION

The main function of the polymer used for tertiary oil recovery isbelieved to increase solution viscosity and decrease water permeabilityin oil layer, so as to decrease mobility ratio and adjust waterinjection profile, and thus to enhance oil recovery by increasing theconformance factor. The solution viscosity and stability of theviscosity are important indicators for determining polymer displacementcharacteristics, and also are the key problem for determining recoveryeffect. With the continuous increase of oilfield comprehensive watercontent, it becomes increasingly difficult to extract oil and keepstable production, thus the requirements on the polymer used fortertiary oil recovery also increase constantly.

Heavy oil recovery is a common problem worldwide. The heavy oil hascharacteristics of high viscosity, high gum asphaltene content or highwax content; heavy oil gathers up about 70% sulfur and 90% nitrogen ofthe crude oil, the light component which accounts for about 70% of thetotal heavy oil is the convertible section by using the currenttechnology, but it is still difficult to convert it efficiently. Theheavy component which accounts for about 20% of the total heavy oil isdifficult to be converted directly by using conventional technology. Therest of the heaviest is 10% of bottom residue of the heavy oil, which isrich in over 70% of metals and over 40% of sulfur and nitrogen, it can'tbe converted effectively into light product. The heavy oil does noteasily flow in the formation, wellbore and oil pipeline. Furthermore,since the oil-water mobility ratio is big, heavy oil can easily causemany problems such as rapid water breakthrough, high water content ofproduced fluid, and easy formation sand production. The process forheavy oil recovery can be mainly divided into recovery of liquidflooding (e.g., hot water flooding, steam huff and puff, steam flood andso on) and recovery of yield enhancement (e.g., horizontal well,compositing branched well, electric heating and etc). A chemicalviscosity reducer can disperse and emulsify the heavy oil effectively,reduce the viscosity of the heavy oil remarkably and decrease the flowresistance of heavy oil in the formation and wellbore, which issignificantly important for reducing energy consumption in the processof recovery, decreasing discharging pollution and enhancing heavy oilrecovery.

BRIEF DESCRIPTION OF THE INVENTION

In the following context of this invention, unless otherwise defined,the same variable group, and molecular and structural formula have thesame definitions.

The instant invention relates to an amphiphilic macromolecule, thisamphiphilic macromolecule has repeating units as described below: astructural unit A for adjusting molecular weight, molecular weightdistribution and charge characteristics, a highly sterically hinderedstructural unit B and an amphiphilic structural unit C.

In an embodiment, the structural unit A for adjusting molecular weight,molecular weight distribution and charge characteristics comprises(meth)acrylamide monomer unit A₁ and/or (meth)acrylic monomer unit A₂.Preferably, the structural unit A includes (meth)acrylamide monomer unitA₁ and/or (meth)acrylic monomer unit A₂ simultaneously. In the art, themolecular weight of the amphiphilic macromolecule may be selected asneeded, preferably, this molecular weight may be selected between1000000-20000000.

Preferably, the (meth)acrylamide monomer unit A₁ has a structure offormula (1):

In formula (1), R₁ is H or a methyl group; R₂ and R₃ are independentlyselected from the group consisting of H and a C₁-C₃ alkyl group; R₂ andR₃ are preferably H.

Preferably, the (meth)acrylic monomer unit A₂ is (meth)acrylic acidand/or (meth)acrylate. Preferably the (meth)acrylate is sodiummethacrylate.

Preferably, the molar percentage of (meth)acrylamide monomer unit A₁ inthe entire amphiphilic macromolecule repeating units is 70-99 mol %;preferably 70-90 mol %, more preferably 72.85-78 mol %.

Preferably, the molar percentage of (meth)acrylic monomer unit A₂ in theentire amphiphilic polymer repeat units is 1-30 mol %; preferably 1-25mol %, and more preferably 20-25 mol %.

In another embodiment, the structural unit A for the regulation ofmolecular weight, molecular weight distribution and chargecharacteristics has a structure of formula (2):

wherein, R₁ is H or a methyl group; R₂ and R₃ are independently selectedfrom the group consisting of H and a C₁-C₃ alkyl group; R₂ and R₃ arepreferably H; R₄ is selected from H or a methyl group; Gr is —OH or—O⁻Na⁺; m and n represent the molar percentages of the structural unitsin the entire amphiphilic macromolecule repeating units, and m is 70-99mol %, preferably 70-90 mol %, more preferably 72.85-78 mol %; n is 1-30mol %, preferably 1-25 mol %, more preferably 20-25 mol %.

In another embodiment, in formula (2), R₁-R₃ are preferably H, and Gr ispreferably —O⁻Na⁺.

In another embodiment, the highly sterically hindered structural unit Bcontains at least a structure G, wherein the structure G is a cyclichydrocarbon structure formed on the basis of two adjacent carbon atomsin the main chain, or is selected from a structure of formula (3), andthe highly sterically hindered structural unit B optionally contains astructure of formula (4):

In formula (3), R₅ is H or a methyl group; preferably H; R₆ is a radicalselected from the group consisting of the structures of formulas (5) and(6).

In formula (5), a is an integer from 1 to 11; preferably 1-7;

In formula (4), R₇ is H or a methyl group; R₈ is selected from the groupconsisting of —NHPhOH, —OCH₂Ph, —OPhOH, —OPhCOOH and salts thereof,—NHC(CH₃)₂CH₂SO₃H and salts thereof, —OC(CH₃)₂(CH₂)_(b)CH₃,—NHC(CH₃)₂(CH₂)_(c)CH₃, —OC(CH₃)₂CH₂C(CH₃)₂(CH₂)_(d)CH₃,—NHC(CH₃)₂CH₂C(CH₃)₂(CH₂)_(e)CH₃, —O(CH₂)_(f)N⁺(CH₃)₂CH₂PhX⁻,

wherein b and c are respectively integers from 0 to 21, preferably from1 to 11; d and e are respectively integers from 0 to 17, preferably from1 to 7; f is an integer from 2 to 8, preferably from 2 to 4; and X⁻ isCP or Br⁻.

Preferably, the highly sterically hindered structural unit B comprises astructure G and a structure of formula (4).

In another embodiment, the cyclic hydrocarbon structure formed on thebasis of two adjacent carbon atoms in the main chain is selected fromthe group consisting of:

Preferably, the molar percentage of structure G of the highly stericallyhindered structural unit B in the entire amphiphilic macromoleculerepeating units is 0.02-2 mol %; preferably 0.02-1.0 mol %, morepreferably 0.05-0.5 mol %.

Preferably, the molar percentage of the structure of formula (4) of thehighly sterically hindered structural unit B in the entire amphiphilicmacromolecule repeating units is 0.05-5 mol %; preferably 0.1-2.5 mol %,more preferably 0.1-1.0 mol %.

In another embodiment, the highly sterically hindered structural unit Bhas a structure of formula (7):

In formula (7), the definition on G is as described above, preferablythe structure of formula (3),

the definitions on R₇ and R₈ are as described in formula (4). x and yrepresent the molar percentages of the structure units in the entireamphiphilic macromolecule repeating units, and x is 0.02-2 mol %,preferably 0.02-1.0 mol %, more preferably 0.05-0.5 mol %; y is 0.05-5mol %, preferably 0.1-2.5 mol %, and more preferably 0.1-1.0 mol %.

In another embodiment, the amphiphilic structural unit C has a structureof formula (8):

In formula (8), R₉ is H or a methyl group; R₁₀ is—N⁺(CH₃)₂(CH₂)_(ξ)CH₃X⁻, —N⁺((CH₂)_(σ)CH₃)₃X⁻ or—N⁺(CH₃)((CH₂)_(τ)CH₃)₂X⁻; ξ is an integer from 3 to 21; σ is an integerfrom 2 to 9; τ is an integer from 3 to 15; X⁻ is Cl⁻ or Br⁻. Preferably,ξ is from 3 to 17, σ is from 2 to 5, τ is from 3 to 11.

Preferably, the molar percentage of amphiphilic structural unit C in theentire amphiphilic macromolecule repeating units is 0.05-10 mol %;preferably 0.1-5.0 mol %, more preferably 0.5-1.8 mol %.

In another embodiment, the amphiphilic macromolecule has a structure offormula (9):

In formula (9), the definitions on R₄, m and n are as described informula (2); the definitions on R₇, R₈, G, x and y are as described informula (7); the definitions on R₉ and R₁₀ are as described in formula(8); z represents the molar percentage of this structural unit in theentire amphiphilic macromolecule repeat units, and z is 0.05-10 mol %,preferably 0.1-5.0 mol %, more preferably 0.5-1.8 mol %.

Specifically, this present invention provides a high molecular compoundhaving a structure of formulas (I)-(X):

The molecular weight of the amphiphilic macromolecule described above isbetween 1000000 and 20000000; preferably between 3000000 and 13000000.

The measurement of the molecular weight M is as follows: The intrinsicviscosity [η] is measured by Ubbelohde viscometer as known in the art,then the obtained intrinsic viscosity [η] value is used in the followingequation to obtain the desired molecular weight M:

M=802[η]^(1.25)

The amphiphilic macromolecule according to this present invention can beprepared by known methods in the art, for example, by polymerizing thestructural unit for adjusting molecular weight, molecular weightdistribution and charge characteristics, the highly sterically hinderedstructural unit and the amphiphilic structural unit in the presence ofan initiator. The polymerization process can be any type well known inthe art, such as, suspension polymerization, emulsion polymerization,solution polymerization, precipitation polymerization, and etc.

A typical preparation method is as follows: the above monomers are eachdispersed or dissolved in an aqueous system under stirring, the monomermixture is polymerized by the aid of an initiator under nitrogenatmosphere to form the amphiphilic macromolecule. The so far existingrelevant technologies for preparing an amphiphilic macromolecule can allbe used to prepare the amphiphilic macromolecule of this invention.

All the monomers for preparing the amphiphilic macromolecule can becommercially available, or can be prepared on the basis of prior arttechnology directly, and some monomers' synthesis are described indetails in specific examples.

DESCRIPTION OF FIGURES

FIG. 1 depicts the relationship of viscosity vs. concentration of theamphiphilic macromolecules obtained from examples 1-5 of the inventionin saline having a degree of mineralization of 3×10⁴ mg/L at atemperature of 85° C.

FIG. 2 depicts the relationship of viscosity vs. temperature of theamphiphilic macromolecules obtained from the examples 1-5 of theinvention in saline having a degree of mineralization of 3×10⁴ mg/L atthe concentration of 1750 mg/L.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is further illustrated below by combining specificexamples; however, this invention is not limited to the followingexamples.

Example 1

This example synthesized the amphiphilic macromolecule of formula (I):

The synthesis of the amphiphilic macromolecule of this example was asfollows:

Firstly, water, accounting for ¾ of the total weight of the reactionsystem, was charged into a reactor, then various monomers, totallyaccounting for ¼ of the total weight of the reaction system, werecharged into the reactor as well, and the molar percentages m, n, x, y,z for each repeating units were 75%, 23%, 0.15%, 0.65%, 1.2% insuccession. The mixture was stirred until complete dissolution, and a pHadjusting agent was then added in to adjust the reaction solution tohave a pH value of about 9, then nitrogen gas was introduced in for 30minutes to remove oxygen contained therein. An initiator was added intothe reactor under the protection of nitrogen gas, and nitrogen gas wasfurther continued for 10 minutes, then the reactor was sealed. Thereaction was conducted at a temperature of 28° C.; after 5 hours, thereaction was ended with a complete conversion. After the drying of theobtained product, powdered amphiphilic macromolecule was obtained. Themolecular weight of the amphiphilic macromolecule was 1160×10⁴.

Example 2

This example synthesized the amphiphilic macromolecule of formula (II).

The synthesis route of the monomer

was as follows:

The synthesis of the amphiphilic macromolecule of this example was asfollows:

Firstly, water, accounting for ¾ of the total weight of the reactionsystem, was charged into a reactor, then various monomers, totallyaccounting for ¼ of the total weight of the reaction system, werecharged into the reactor as well, and the molar percentages m, n, x, y,z for each repeating units were 75%, 24%, 0.15%, 0.1%, 0.75% insuccession. The mixture was stirred until complete dissolution, and a pHadjusting agent was then added in to adjust the reaction solution tohave a pH value of about 8, then nitrogen gas was introduced in for 40minutes to remove oxygen contained therein. An initiator was added intothe reactor under the protection of nitrogen gas, and nitrogen gas wasfurther continued for 10 minutes, then the reactor was sealed. Thereaction was conducted at a temperature of 25° C.; after 5.5 hours, thereaction was ended with a complete conversion. After the drying of theobtained product, powdered amphiphilic macromolecule was obtained. Themolecular weight of the amphiphilic macromolecule was 730×10⁴.

Example 3

This example synthesized the amphiphilic macromolecule of formula (III):

The synthesis route of the monomer

was as follows:

The synthesis of the amphiphilic macromolecule of this example was asfollows:

Firstly, water, accounting for ¾ of the total weight of the reactionsystem, was charged into a reactor, then various monomers, totallyaccounting for ¼ of the total weight of the reaction system, werecharged into the reactor as well, and the molar percentages m, n, x, y,z for each repeating units were 77%, 21%, 0.25%, 0.25%, 1.5% insuccession. The mixture was stirred until complete dissolution, and a pHadjusting agent was then added in to adjust the reaction solution tohave a pH value of about 9, then nitrogen gas was introduced in for 30minutes to remove oxygen contained therein. An initiator was added intothe reactor under the protection of nitrogen gas, and nitrogen gas wasfurther continued for 10 minutes, then the reactor was sealed. Thereaction was conducted at a temperature of 23° C.; after 5 hours, thereaction was ended with a complete conversion. After the drying of theobtained product, powdered amphiphilic macromolecule was obtained. Themolecular weight of the amphiphilic macromolecule was 720×10⁴.

Example 4

This example synthesized the amphiphilic macromolecule of formula (IV):

The synthesis route of the monomer

was as follows:

The synthesis of the amphiphilic macromolecule of this example was asfollows:

Firstly, water, accounting for ¾ of the total weight of the reactionsystem, was charged into a reactor, then various monomers, totallyaccounting for ¼ of the total weight of the reaction system, werecharged into the reactor as well, and the molar percentages m, n, x, y,z for each repeating units were 75%, 23%, 0.05%, 0.15%, 1.8% insuccession. The mixture was stirred until complete dissolution, and a pHadjusting agent was then added in to adjust the reaction solution tohave a pH value of about 9, then nitrogen gas was introduced in for 30minutes to remove oxygen contained therein. An initiator was added intothe reactor under the protection of nitrogen gas, and nitrogen gas wasfurther continued for 10 minutes, then the reactor was sealed. Thereaction was conducted at a temperature of 28° C.; after 5 hours, thereaction was ended with a complete conversion. After the drying of theobtained product, powdered amphiphilic macromolecule was obtained. Themolecular weight of the amphiphilic macromolecule was 460×10⁴.

Example 5

This example synthesized the amphiphilic macromolecule of formula (V):

The synthesis route of the monomer

was as follows

The synthesis of the amphiphilic macromolecule of this example was asfollows:

Firstly, water, accounting for ¾ of the total weight of the reactionsystem, was charged into a reactor, then various monomers, totallyaccounting for ¼ of the total weight of the reaction system, werecharged into the reactor as well, and the molar percentages m, n, x, y,z for each repeating units were 78%, 20%, 0.2%, 1%, 0.8% in succession.The mixture was stirred until complete dissolution, and a pH adjustingagent was then added in to adjust the reaction solution to have a pHvalue of about 10, then nitrogen gas was introduced in for 30 minutes toremove oxygen contained therein. An initiator was added into the reactorunder the protection of nitrogen gas, and nitrogen gas was furthercontinued for 10 minutes, then the reactor was sealed. The reaction wasconducted at a temperature of 25° C.; after 6 hours, the reaction wasended with a complete conversion. After the drying of the obtainedproduct, powdered amphiphilic macromolecule was obtained. The molecularweight of the amphiphilic macromolecule was 580×10⁴.

Example 6

This example synthesized the amphiphilic macromolecule of formula (VI):

The synthesis of the amphiphilic macromolecule of this example was asfollows:

Firstly, water, accounting for ¾ of the total weight of the reactionsystem, was charged into a reactor, then various monomers, totallyaccounting for ¼ of the total weight of the reaction system, werecharged into the reactor as well, and the molar percentages m, n, x, y,z for each repeating units were 73%, 24%, 0.5%, 1%, 1.5% in succession.The mixture was stirred until complete dissolution, and a pH adjustingagent was then added in to adjust the reaction solution to have a pHvalue of about 8, then nitrogen gas was introduced in for 30 minutes toremove oxygen contained therein. An initiator was added into the reactorunder the protection of nitrogen gas, and nitrogen gas was furthercontinued for 10 minutes, then the reactor was sealed. The reaction wasconducted at a temperature of 55° C.; after 3 hours, the reaction wasended with a complete conversion. After the drying of the obtainedproduct, powdered amphiphilic macromolecule was obtained. The molecularweight of the amphiphilic macromolecule was 770×10⁴.

Example 7

This example synthesized the amphiphilic macromolecule of formula (VII):

The synthesis of the amphiphilic macromolecule of this example was asfollows:

Firstly, water, accounting for ¾ of the total weight of the reactionsystem, was charged into a reactor, then various monomers, totallyaccounting for ¼ of the total weight of the reaction system, werecharged into the reactor as well, and the molar percentages m, n, x, y,z for each repeating units were 77%, 22%, 0.25%, 0.25%, 0.5% insuccession. The mixture was stirred until complete dissolution, and a pHadjusting agent was then added in to adjust the reaction solution tohave a pH value of about 9, then nitrogen gas was introduced in for 30minutes to remove oxygen contained therein. An initiator was added intothe reactor under the protection of nitrogen gas, and nitrogen gas wasfurther continued for 10 minutes, then the reactor was sealed. Thereaction was conducted at a temperature of 55° C.; after 2 hours, thereaction was ended with a complete conversion. After the drying of theobtained product, powdered amphiphilic macromolecule was obtained. Themolecular weight of the amphiphilic macromolecule was 920×10⁴.

Example 8

This example synthesized the amphiphilic macromolecule of formula(VIII):

The synthesis of the amphiphilic macromolecule of this example was asfollows:

Firstly, water, accounting for ¾ of the total weight of the reactionsystem, was charged into a reactor, then various monomers, totallyaccounting for ¼ of the total weight of the reaction system, werecharged into the reactor as well, and the molar percentages m, n, x, y,z for each repeating units were 72.85%, 25%, 0.15%, 1%, 1% insuccession. The mixture was stirred until complete dissolution, and a pHadjusting agent was then added in to adjust the reaction solution tohave a pH value of about 10, then nitrogen gas was introduced in for 30minutes to remove oxygen contained therein. An initiator was added intothe reactor under the protection of nitrogen gas, and nitrogen gas wasfurther continued for 10 minutes, then the reactor was sealed. Thereaction was conducted at a temperature of 55° C.; after 3 hours, thereaction was ended with a complete conversion. After the drying of theobtained product, powdered amphiphilic macromolecule was obtained. Themolecular weight of the amphiphilic macromolecule was 430×10⁴.

Example 9

This example synthesized the amphiphilic macromolecule of formula (IX):

The synthesis of the amphiphilic macromolecule of this example was asfollows:

Firstly, water, accounting for ¾ of the total weight of the reactionsystem, was charged into a reactor, then various monomers, totallyaccounting for ¼ of the total weight of the reaction system, werecharged into the reactor as well, and the molar percentages m, n, x, y,z for each repeating units were 75%, 23%, 0.25%, 0.25%, 1.5% insuccession. The mixture was stirred until complete dissolution, and a pHadjusting agent was then added in to adjust the reaction solution tohave a pH value of about 8, then nitrogen gas was introduced in for 30minutes to remove oxygen contained therein. An initiator was added intothe reactor under the protection of nitrogen gas, and nitrogen gas wasfurther continued for 10 minutes, then the reactor was sealed. Thereaction was conducted at a temperature of 50° C.; after 2.5 hours, thereaction was ended with a complete conversion. After the drying of theobtained product, powdered amphiphilic macromolecule was obtained. Themolecular weight of the amphiphilic macromolecule was 690×10⁴.

Example 10

This example synthesized the amphiphilic macromolecule of formula (X):

The synthesis of the amphiphilic macromolecule of this example was asfollows:

Firstly, water, accounting for ¾ of the total weight of the reactionsystem, was charged into a reactor, then various monomers, totallyaccounting for ¼ of the total weight of the reaction system, werecharged into the reactor as well, and the molar percentages m, n, x, y,z for each repeating units were 75%, 23%, 0.25%, 0.25%, 1.5% insuccession. The mixture was stirred until complete dissolution, and a pHadjusting agent was then added in to adjust the reaction solution tohave a pH value of about 8, then nitrogen gas was introduced in for 30minutes to remove oxygen contained therein. An initiator was added intothe reactor under the protection of nitrogen gas, and nitrogen gas wasfurther continued for 10 minutes, then the reactor was sealed. Thereaction was conducted at a temperature of 50° C.; after 4 hours, thereaction was ended with a complete conversion. After the drying of theobtained product, powdered amphiphilic macromolecule was obtained. Themolecular weight of the amphiphilic macromolecule was 830×10⁴.

Measurement Examples Measurement Example 1

Saline having a mineralization degree of 3×10⁴ mg/L was used to prepareamphiphilic macromolecule solutions with different concentrations, andthe relationship between the concentration, temperature and theviscosity of the solution was determined. The results were shown in FIG.1 and FIG. 2.

The figures showed that the amphiphilic macromolecule solutions ofexamples 1-5 still have favorable viscosifying capacity under thecondition of high temperature and high degree of mineralization. Thehighly sterically hindered unit in the amphiphilic macromolecule reducedthe rotational degree of freedom in the main chain and increased therigidity of the macromolecule chain, which made the macromolecule chaindifficult to curl and tend to stretch out, thus enlarging thehydrodynamic radius of the macromolecule; in the meantime, theamphiphilic structural unit associated each other to form themicrodomain by intramolecular- or intermolecular-interaction, thusenhancing the viscosifying capacity of the solution remarkably under theconditions of high temperature and high salinity.

Measurement Example 2

Testing method: Under a testing temperature of 25° C., 25 ml electricdehydration crude oil samples from three types of oilfields were addedin a 50 ml test tube with a plug, then 25 ml aqueous solutions ofamphiphilic macromolecule with different concentrations formulated withdistilled water were added in. The plug of the test tube was tightened,then the test tube was shaken manually or by using an oscillating boxfor 80-100 times in horizontal direction, and the shaking amplitudeshould be greater than 20 cm. After sufficient mixing, the plug of thetest tube was loosed. Viscosity reduction rate for crude oil wascalculated according to the following equation:

${{Viscosity}\mspace{14mu} {reduction}\mspace{14mu} {{rate}(\%)}} = {\frac{{{viscosity}\mspace{14mu} {of}\mspace{14mu} {crude}\mspace{14mu} {oil}\mspace{14mu} {sample}} - {{viscosity}\mspace{14mu} {after}\mspace{14mu} {mixing}}}{{viscosity}\mspace{14mu} {of}\mspace{14mu} {crude}\mspace{14mu} {oil}\mspace{14mu} {sample}} \times 100}$

TABLE 1 Experimental results of the heavy oil viscosity reduction of theamphiphilic macromolecule obtained from the example 6 to example 10(oil-water ratio 1:1, 25) oil-water volume ratio (1:1) oil viscosity oilviscosity oil viscosity test temperature sample reduction samplereduction sample reduction (25° C.) 1 rate(%) 2 rate(%) 3 rate(%)initial viscosity (mPa · s) 1650 — 5100 — 16000 — Example 6 400 mg/L 73055.76 1750 65.69 7100 55.63 600 mg/L 470 71.52 1250 75.49 3250 79.69 800mg/L 330 80.00 950 81.37 1850 88.44 1000 mg/L  295 82.12 820 83.92 150090.63 1200 mg/L  270 83.64 675 86.76 1225 92.34 Example 7 400 mg/L 78052.73 1800 64.71 7700 51.88 600 mg/L 590 64.24 1350 73.53 4200 73.75 800mg/L 460 72.12 1100 78.43 2850 82.19 1000 mg/L  340 79.39 880 82.75 190088.13 1200 mg/L  300 81.82 790 84.51 1500 90.63 Example 8 400 mg/L 82050.30 1475 71.08 5650 64.69 600 mg/L 590 64.24 1200 76.47 3950 75.31 800mg/L 450 72.73 850 83.33 2600 83.75 1000 mg/L  375 77.27 670 86.86 145090.94 1200 mg/L  330 80.00 620 87.84 1290 91.94 Example 9 400 mg/L 78052.73 1450 71.57 5800 63.75 600 mg/L 450 72.73 1150 77.45 4100 74.38 800mg/L 360 78.18 850 83.33 2500 84.38 1000 mg/L  280 83.03 680 86.67 157090.19 1200 mg/L  260 84.24 620 87.84 1390 91.31 Example 10 400 mg/L 71056.97 1450 71.57 5270 67.06 600 mg/L 500 69.70 1050 79.41 3100 80.63 800mg/L 410 75.15 830 83.73 1890 88.19 1000 mg/L  320 80.61 675 86.76 120092.50 1200 mg/L  270 83.64 650 87.25 950 94.06

Table 1 showed that the amphiphilic macromolecules of examples 6-10 hadgood effects for viscosity reduction as to all three oil samples. Withthe increase of the concentration of the amphiphilic macromoleculesolution, the viscosity reduction rate increased. And, when theconcentration of the amphiphilic macromolecule solution was the same,the viscosity reduction rate increased with the enhancing of theviscosity of the oil sample. It was believed that the amphiphilicmacromolecule could reduce the viscosity of the crude oil remarkably viaa synergetic effect between the highly sterically hindered structuralunit and the amphiphilic structural unit, which could emulsify anddisperse the crude oil effectively.

INDUSTRIAL APPLICATION

The amphiphilic macromolecule of this invention can be used in oilfielddrilling, well cementing, fracturing, crude oil gathering andtransporting, sewage treating, sludge treating and papermaking, and itcan be used as intensified oil producing agent and oil displacing agent,heavy oil viscosity reducer, fracturing fluid, clay stabilizer, sewagetreating agent, retention aid and drainage aid and strengthening agentfor papermaking.

The amphiphilic macromolecule of this invention is especially suitablefor crude oil exploitation, for instance, it can be used as anintensified oil displacement polymer and a viscosity reducer for heavyoil. When it is used as an oil displacement agent, it has remarkableviscosifying effect even under the condition of high temperature andhigh salinity, and can thus enhance the crude oil recovery. When it isused as a viscosity reducer for heavy oil, it can remarkably reduce theviscosity of the heavy oil and decrease the flow resistance thereof inthe formation and wellbore by emulsifying and dispersing the heavy oileffectively.

1-13. (canceled)
 14. An amphiphilic macromolecule comprising: asrepeating units, it has a structural unit A for adjusting molecularweight, molecular weight distribution and charge characteristics, ahighly sterically hindered structural unit B and an amphiphilicstructural unit C, wherein the amphiphilic structural unit C has astructure of formula (8):

in formula (8), R₉ is H or a methyl group; R₁₀ is—N⁺(CH₃)₂(CH₂)_(ξ)CH₃X⁻, —N⁺((CH₂)_(σ)CH₃)₃X⁻ or—N⁺(CH₃)((CH₂)_(τ)CH₃)₂X⁻; ξ is an integer from 3 to 21; σ is an integerfrom 2 to 9; τ is an integer from 3 to 15; and X⁻ is Cl⁻ or Br⁻.
 15. Theamphiphilic macromolecule as claimed in claim 14, wherein the structuralunit A for adjusting the molecular weight, molecular weight distributionand charge characteristics comprises a (meth)acrylamide monomer unit A₁and/or a (meth)acrylic monomer unit A₂.
 16. The amphiphilicmacromolecule as claimed in claim 14, wherein the highly stericallyhindered structural unit B contains a structure G, the structure G is acyclic hydrocarbon structure formed on the basis of two adjacent carbonatoms in the main chain, or is selected from a structure of formula (3),and the highly sterically hindered structural unit B optionally containsa structure of formula (4):

wherein in formula (3), R₅ is H or a methyl group; R₆ is a radicalselected from the structures of formula (5) and formula (6),

in formula (5), a is an integer from 1 to 11, in formula (4), R₇ is H ora methyl group; R₈ is selected from the group consisting of —NHPhOH,—OCH₂Ph, —OPhOH, —OPhCOOH and salts thereof, —NHC(CH₃)₂CH₂SO₃H and saltsthereof, —OC(CH₃)₂(CH₂)_(b)CH₃, —NHC(CH₃)₂(CH₂)_(c)CH₃,—OC(CH₃)₂CH₂C(CH₃)₂(CH₂)_(d)CH₃, —NHC(CH₃)₂CH₂C(CH₃)₂(CH₂)_(e)CH₃,—O(CH₂)_(f)N⁺(CH₃)₂CH₂PhX⁻,

wherein b and c are integers from 0 to 21 respectively; d and e areintegers from 0 to 17 respectively; f is an integer from 2 to 8; and X⁻is Cl⁻ or Br.
 17. The amphiphilic macromolecule as claimed in claim 15,wherein based on 100 mol % of the entire amphiphilic macromoleculerepeating units, the molar percentage of the (meth)acrylamide monomerunit A₁ is 70-99 mol %; and the molar percentage of the (meth)acrylicmonomer unit A₂ is 1-30 mol %.
 18. The amphiphilic macromolecule asclaimed in claim 16, wherein based on 100 mol % of the entireamphiphilic macromolecule repeating units, the molar percentage of thestructure G is 0.02-2 mol %; and the molar percentage of the structureof formula (4) is 0.05-5 mol %.
 19. The amphiphilic macromolecule asclaimed in claim 14, wherein based on 100 mol % of the entireamphiphilic macromolecule repeating units, the molar percentage of thestructure of formula (8) is 0.05-10 mol %.
 20. The amphiphilicmacromolecule as claimed in claim 14, wherein the structural unit A foradjusting molecular weight, molecular weight distribution and chargecharacteristics has a structure of formula (2);

wherein in formula (2), R₁ is H or a methyl group; R₂ and R₃ areindependently selected from the group consisting of H and a C₁-C₃ alkylgroup; R₄ is selected from the group consisting of H and a methyl group;Gr is —OH or —O⁻Na⁺; m and n represent the molar percentages of thestructural units in the entire amphiphilic macromolecule, and m is from70 to 99 mol %; n is from 1 to 30 mol %.
 21. The amphiphilicmacromolecule as claimed in claim 16, wherein the cyclic hydrocarbonstructure formed on the basis of the two adjacent carbon atoms in themain chain is selected from the group consisting of:


22. The amphiphilic macromolecule as claimed in claim 16, wherein thehighly sterically hindered structural unit B has a structure of formula(7):

wherein in formula (7); the definitions on R₇ and R₈ are as described informula (4); x and y respectively represent the molar percentages of thestructural units in the entire amphiphilic macromolecule, and x is from0.02 to 2 mol %, y is from 0.05 to 5 mol %.
 23. The amphiphilicmacromolecule as claimed in claim 14, wherein the amphiphilicmacromolecule has a structure of formula (9):

in formula (9), the definitions on R₄, m and n are as described informula (2); the definitions on R₇, R₈, G, x and y are as described informula (7); the definitions on R₉ and R₁₀ are as described in formula(8); z represents the molar percentage of this structural unit in theentire amphiphilic macromolecule repeating unit, and z is from 0.05 to10 mol %.
 24. The amphiphilic macromolecule as claimed in claim 14,which is a compound of formulas (I)-(X):


25. The amphiphilic macromolecule as claimed in claim 14, wherein theamphiphilic macromolecule has a molecular weight of between1000000-20000000.
 26. The amphiphilic macromolecule as claimed in claim14 for use in oilfield drilling, well cementing, fracturing, crude oilgathering and transporting, sewage treating, sludge treating andpapermaking as intensified oil producing agent and oil displacing agent,heavy oil viscosity reducer, fracturing fluid, clay stabilizer, sewagetreating agent, retention aid and drainage aid and strengthening agentfor papermaking.